Circuit breaker



April 18, 1939- w. M. LEEDS arm. 2,154,515-

6 IRCUIT BREAKER Filed May 29, 1936 5 Sheets-Sheet l INVENTORS. hmlbrapM 1:203 000 fBY 7,

ATTORNEY CIRCUIT BREAKER Filed May 29, 1936 5 Sheets-Sheet 5 INVENTORSMn/h op Be/ Mleeafr and am? PBa/ref. BY 1/ ATTORN E April 1939- w. M.LEEDS ET AL v 2,154,515

CIRCUIT BREAKER Filed May 29, 1936 5 Sheets-Sheet 4 1 j v I Ben PB k vjam! a/re/T- Wwz 5M 4 ATTOR' Y iii 18, 1939. w M, LEEDS AL I 2,154,515

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CIRCUIT BREAKER Filed May 29, 1936 5 Sheets-Sheet 5 WITNESSES: rINVENTORS Mn/h ropM deed and Patented is, 1939 ATENT- orrlcs joracm'raasax'sa winum u. Leeds, Wilkinsbnrg, and mP.Baker,'lnrtleCreek,Pa.,anlgnmtoWest-.

sylvania I Application my 29, 1986, N o. 82,40

This invention relates to circuit breakers and more-particularly to areextinguishing devices therefor. In the copending applications of W. M.Leeds, Serial No. 697.647, flied November 11,

v 1933, now Patent No..2,l02,326 issued December 14, 1937, and H. J.Lingal and R. C. Dickinson. Serial No. 743,697, illed September 12,1934, now Patent No. 2,112,033 issued March 22, 1938, both assigned tothe assignee of this application, are 10 extinguishing devices aredisclosed which comprise a plurality of insulating plates arranged instacks and having narrow aligned slots therein so as to provide a narrowchamber or passage of considerable length in which an arc-may be lldrawn longitudinally thereof by the separation of suitable contactmembers. Thearc thus drawn is moved laterally in the slot-like passageand acts-upon a material such as oil or other suitable arc quenchingmedia positioned along the walls or the passage to produce a gas whichis intermixed with the arc stream to such an extent that the are streamis deionized and the are extinguished. Arc movement in each of the aboveapplications is obtained by a magnetic-fieldset up by coil or coilsinserted in the arccircuit when the are is caused to transfer from themain contacts to are horns which are connected in parallel with the maincontacts through the iield coils. Transfer of the are from the maincontacts to the arc horns is accomplished by drawing the moving contactmember closely adjacent the arc receiving tips of the horns and thenmoving it a distance beyond the horns so that the main contact sepa-'ration exceeds that of the arc horns. Inasmuch less than that betweenthe main contacts, transfer ofthe are from the main contacts to thehorns takes place. -We have found, however,

that an arrangement for are movement, as above 10 described, is notreliable over as wide a range of current values as is desirable for someapplications. Particularly during the interruption of currents of lowvalue as may be experienced at light or normal line loads, diiiicultymight be exmovement from the main contacts to the arcing. so The presentday requirement for circuit 5 as the resistance to are flow across thehorns is 11 China (a. zoo-m) breakers capableof interrupting highvoltages in very short periods of time has led to the production of adesign embodyinga plurality of breaks considerably in excess of thesimple double break construction used in the past. Inasmuch s as thevoltage appearing across each break of a multiple break interrupter ismuch less than that across the breaks of a double break structure,considerably less individual gap separation is re-'- quired. Thus, sincethe time required to attain 10 the total gap separation varies inverselywith the number 01' breaks, any number of breaks in excess of two willgreatly diminish the time required for electrode separation. However,the use of a large number of breaks in series necessitates the multillplieation of the are extinguishing structures and, therefore,complicates the are moving means.

'The requirement for more rapid arc extinguishment complicates the aremoving problem still further in that it calls for a more rapid arc move-D ment within the individual arc extinguishing units than has beenheretofore practiced.

A further object of our invention, therefore, is a to provide an arcextinguishing structure in which the are moving means are highlyeflicient and 85 capable of moving the are at such velocities necessaryto meet the requirements of high speed-arc extinguishment.

. A still further obiect of our invention is to provide an arrangementof the are moving coils and 80 the connections thereof for a multiplebreak arc extinguisher wherein emcient high speed are movement may beobtained with a minimum number of parts.

A more specific object of our invention is to 35.

provide a circuit interrupter in which the main contact members inaddition to their current carrying function when the breaker is closed,also function to establish the are within the arc extinguishingstructure, and in which movement .4

' ture embodying our invention, showing the breake'r-tank partially incross section to reveal the are extinguishing assemblages therefor;

Pig. 2 is a longitudinal sectional view taken through the upper portionof one of the are extinguishing assemblages showing the arc moving coilsof the uppermost arc extinguishing unit and the coil connections to thenext adjacent arc extinguishing unit;

Fig. 3 is a fragmentary sectional view of the lowermost arcextinguishing unit, showing the are moving coils used therein;

Fig. 4 is a perspective view of one of the arc moving coils;

Fig. 5 is a partial sectional view taken along line V--V of Fig. 4;

Fig. 6 is a cross sectional view showing the arc passage of an arcextinguishing unit as taken I along line VI--VI of Fig. 2;

Fig. '7 is a fragmentary developed sectional view of the arc passage;and

Fig. 8 is a circuit diagram of the coil connections of one of the arcassemblages of the breaker of our invention.

Referring to the drawings, the reference numeral l0 designates anenclosure or tank provided with two insulating bushings I3, mounted uponthe upper wall of the tank l3 and extending interiorly thereof. Each ofthe bushings l2 encloses a metallic lead-in conductor I3, the lower endsof which are adapted to support an arc extinguishing assemblagegenerally indicated at IS. The two arc extinguishing assemblages ii areelectrically joined by a bridging bar I1 having releasable engagementwith spring-pressed contacts 19 in circuit with thearc extinguishingassemblage. The bridging member I! is adapted to'be moved into and 'outof engagement with the contacts I! by means of a lift rod 21 which isactuated by a suitable mechanism, not shown.

Each of the arc extinguishing assemblages I 3 includes a plurality of,in this instance five, arc extinguishing units 33. Each of the units 23comprises a stack of, in this instance fifteen, circular insulatingplates. plates 25 and 21 alternately placed. The plates 21 arerelatively thin and have a curved slot 23 therein, as shown in Fig. 6for defining the walls of an arc passage. The plates 23 which haveconsiderably greater thickness than the plates 21 are provided withindentures or recesses 3| adjacent the slot 23 sons to form pockets forretaining an additional quantity of arc extinguishing fluid within theslot-like e.

The ends of the stack of plates 33 and 31 are provided with an end plate33 also of insulating material, each of which carry an arc horn 33having an arcuate configuration which enables it to extend into the slot23. Adjacent each insulating end plate 33 is secured a metallic endplate 31 preferably of magnetic material. The entire arc extinguishingassemblage including plates 25, 21, 33 and 31 are adapted to be heldtogether inv clamping engagement by means of tie rods 39 preferably ofinsulating material passing through suitable apertures in the respectiveplates. The general stack structure-of each of the arc extinguishingunits 33 is similar and the entire arc extinguishing assemblage I3 isadapted to be assembled upon suitable tie rods not shown, and maintainedin proper spaced relation with respect to each other.

The uppermost unit 33 of each assemblage l3 has secured thereto acontact foot 4| which, in turn, has threaded engagement with the lowerend of its respective lead-in terminal l3 and thereby provides a supportfor the entire are extinguishing assemblage. Each of the areextinguishing units 23 is provided with a pair of contacts,'the fixedone of which, indicated at 43,

The stack is formed of extends through a suitable aperture in the upperend plate 33 downwardly into the slot or are passage 39 and a movablecontact 45. which extends through a suitable guide member 41 extendingthrough both the lower end plates 33 and 31, the movable contact 45 isadapted to be brought into and out of engagement with the fixed contact43 by a suitable straight line linkage mechanism generally indicated at49 which, in turn, is coupled to a common actuating rod 5| by means of acoupling pin 53. The actuating rod 51 is adapted to pass centrallythrough suitable apertures formed in the stack of plates comprising eachof the units 23. The upper end of the operating rod Si is provided witha follower 55 adapted for reciprocating movement in a cylindrical guidemember 51 mounted upon the upper plate 31 of the uppermost unit 23.Secured integrally to the follower 55 is a guide rod 59 about which isplaced an accelerating spring 6| which, in turn, is interposed betweenthe end of the cylindrical guide member 51 and the upper end of thefollower 55.

The lower end of the operating rod 5!, as more clearly shown in Fig. 3,is provided with the releasable contact member l9 previously referred towhich makes both electrical and mechanical connection with the bridgingbar i1. Thus when the lift rod 2| is released pursuant to certainconditions when it is desirable to open the breaker contacts, theaccelerating spring 3i will forcefully drive the operating rod 5i'downwardly which, through its connection with the respective straightline operating linkages 49, will actuate each of the contacts 45 of therespective arc extinguishing units 23 to the open position.

It will thus be seen as the contact 45 in each unit 23 of the two areassemblages l5 separate simultaneously, an arc will be drawn betweeneach of the contacts 43 and 45. The ends of the arc horns 35 positionedadjacent the contacts 43 and 43 are provided with are receiving tips 33and 33, as more clearly shown in Fig. 7. It will benoted that theopposed arc receiving tips 33 and 33 provide diverging arc terminalsurfaces for the ends of the are so that during the initial movementthereof the arc will be progressively lengthened thereby aiding in itsextinguishment. Now, in order to obtain efiective movement of the arefrom the contacts 43 and 43 on to the arc horns 33,disposed-respectively in the upper and lower end of the arc passage 39,two separate and distinct electromagnetic means are employed. The

first means comprises what may be termed a se-.

ries coil 33 positioned in an annular recess 31 provided in the uppermetallic end plate 31 of each arc extinguishing unit 33. One end of thecoil 33 is directly connected with the fixed contact 43 as clearly shownin Figs. 2, 4 and 5. In fact, the coil 33 also provides the necessarymechanical support for the fixed contact 43. The other end of the coil33 is connected by means of a screw 33 to a conductor strip 1| which, inturn, is connected by means of a bridgin bar 13 to thecontact foot.Theturns ofthecoil 33 are insulated from each other and from the wallsof the annular recess 31 by suitable insulation, as

shown. Itwillthusbeseenthatcm'rentfiowing from the incoming terminal I 3through the contact foot 41, bridging bar 13, the conductor 1|,

coil 33 and contacts 43 and 43 will produce a radial magnetic fieldacross the arcuate slot-like passage 23. This field is augmented andintensifiedattheupperendoftheslotbyvirmeofthe magnetic materialcomprising the upper end plate I! in which the coil' OI is embedded.

It therefore follows that as soon as the contacts ii and I semrate, anare drawn therebetween will be. acted upon by this radial mag neticfield produced by the coil 8' to move at least the upper end oi the areinto engagement with the upper are receiving horn 3'. Since the currentcarrying capacity of the series coil '8 ,must be equivalent to that ofthe contacts I! and 45, the required cross section limits in practicethe number of turns to considerably fewer than are necessary to move theare at a speed which will produce the most eil'ective arc extinguishing5 action. Therefore, additional means for moving the arc are'requiredwhich, however, will be brought into play only during the arcextinguishing process. These means are provided by a second coil i5 alsopositioned in the annular recess 1 C1 in the upper end plate Ii and asimilar 0011 located in a similar annular recess 'I'l positioned in thelower end plate II. The two annularly shaped coils 15 positioned in theend plates II [are preferably of edge-wound construction, as 5 shown,and have a considerably larger number of turns than the series type coil05 previously described. y In order to simplify the description, thecoils 15 will hereinafter be referred to as shunt coils by virtue of thefact that they are connected, as will appear, in parallel with thecontacts is and 45, while the coil II will be referred to as a seriescoil since it is connected directly in series with the contacts 43 andll. The uppercoil I! 5 has one end thereof connected by a lead II to theconnector strip 1i which in turn makes con- \tact between the contactfoot ii and one end of the series coil 65. The other endof the uppercoil 15 is connected to the upper, arc horn II. It, ,"therefore'foll'owsthat as soon as the upper end of the are drawn between'the contacts 43and ii is shifted by virtue of the magnetic-field produced by the-coil65 on to the upper arc horn 3| that the upper coil 15 will be insertedinthe arc circuit, thus current flowing through the coil ll will create astrong radial magnetic field across the upper end of the passage 28 tofurther the movement'ofthe are along the upper horn 3i. The foregoingdescription has proceeded on p the assumption that, the circuit throughthe moving contact 4 was completed so as to make possible the flow ofcurrent through theparticular .collsabove referred to. The particularcircuit connections by-which the flow of current through 5 themovingcontact 46 and through the lower shunt coil II of each unit isaccomplished will 1 now be described.

a flexible shunt 1's interconnects the lower end of the moving contactswith a bracket ll ywhich, in turn, makes electrical connection throughstuds '3 with the lower metallic end plate 31. The lower end plate 31 isconnected by a bridging member II to the upper end plate.

31 of the next adjacent unit 23, the conducting 5 member I!interconnects the bridsins connec-' 23 to the fixed contact 4!. Thelower end plate;- 31 of the uppermost unit 13 is also directly connectedby means of a screwjl and afconnecting stud 93 .to the lower arc hornIii Thelower arc- 5 horn 35, in turn, makesconnection with one endtinguishing assemblage.

However, since it is of the lower shunt coil (II while theother endof'thelower shuntcoilflihasa'leadllioining the lead OI'of one end of theupper shunt coil lb of the-next lower unit 23. The other end of thelast-named shunt coil II is connected to the arc horn I! of itsrespective unit in the manner previously described;

The connections for both the series coil II and the shunt coils II forsucceeding units are identics! and it is deemed not necessary todescribe them in detail. It will be noted, however, that only one seriescoil I, positioned in the upper end plate 31, is used in be first fourunits II, whereas the lowermost unit ll has a series coil in both theupper and lower metallic end platu II. The reason for this particulararrangement will be made apparent subsequently in connection with aconsideration of the circuit connec tions'of the coil system of theentire are ex- In order to maintain uniform magnetic circuits for boththe upper and lower end plates I! throughout all of the stacks, theannular recess 11 in the lower end'plate I! of each unity is means of anannular, plate ill preferablymade of insulating material.

, In the lower end plate 11 of the lowermost unit,

'a series coil is employed. With particular reference to Fig. 3, thecoil desilnntedat I; in

general outline. is similar to theseries coil 6. in the lower end plate31, it must be provided with a suitable aperture to permit the movementof the lowermost contact 4i therethrough. The series coil III alsodiifers from the coil I! in that it does not have a fixed contactsecured thereto as does the coil in the latter instance. As shown inFig. 13, the moving contact 48 is connected as previously describedthrough a flexible shunt II to a bracket ill. The bracket i" is-mountedupon the end plate I! and makes electrical contact therewith, and, inturn, is electrically connected by means of a screw ill to (amend of theseries coil Ill. The other end of the series coil ill makes connectionthrough a screw lllto a bracket III which is mounted upon the endplaten-but insulated therefrom by an insulating plate ill. Electricalconnection from the bracket III is taken by meansof a flexible conductorH5 having one end secured to the bracket ill by a bolt ill and havingits other end connected to one of the pair of releasable contacts I!mounted upon the lower end of the operating rod II. The lower arc hornii of the lowermost unit, as shown in- Fig; 3, is also connectedto oneend of the lower shunt coil II, the other end of the coil II beingconnected by the screw ill to the lower end plate. 31 of that unit.

A more complete understandingof the respective coil connections and thearc extinguishing operation will be had from aconsideration of theschematic circuit diagram shown in 'Fig. 8. With particular reference tothe diagram of Fig. 8,

the same characters of reference as used in connection with thedescription of the'foregolng flgures'will be. employed. The conductor llrepresents the lead-in terminal I! heretofore described and isshownmaking electrical connection with the upper end plate 81. Assuming thenwill be from the terminal I3, end plate 31, series coil 55, contact 43,contact 45, shunt connection I9, lower end plate 31, connection 55,which joins the upper end plate 31 of the next adjacent unit 23, fromwhence the circuit is identical through the succeeding units with theexception of the connection from the lower end plate 31 of the lowermostunit 23. This plate is connected to one end of the series coil I03, theother end of which is connected to the movable spring contacts I9. Thereleasable spring contacts I9 during the closing position of the breakerof one of the arc extinguishing assemblages I5 is adapted to beconnected to the releasable spring contacts I 9 of the other arcextinguishing assemblage I5 by means of the bridging bar I1. Thus thecircuit through to the other are extinguishing assemblage is identicalwith that just described and terminates at the other lead in terminal I3of the breaker.

In the opening operation of the breaker to be subsequently described,reference will only be had to the operation of one of the arcextinguishing units I5, it being, of course, understood that theoperation of the other unit I5 which is identical in construction willbe similar. Upon the opening of the breaker contacts in response tooverload or other predetermined conditions, the lift rod 2I is releasedfrom its closed or holding position which permits each of the operatingrods -5I to be moved downwardly under the action of the acceleratingspring 6| to move each of the movable contacts 45 to the open position.It will be noted that since the series coil 65 and the series coil I03are connected in series with the contacts 43 and 45 a radical magneticfield will be maintained across the arc passage 29 when the contacts areclosed and when an arc is playing therebetween. Thus as soon as thecontacts 45 separate from the contacts 43, the entire arc will be actedupon by the magnetic field produced by the series coil 65. But since theupper ends of the respective arcs are subjected to a more in tensefield, these portions will be shifted from the fixed contacts 43 to thereceiving tips of each of the upper arc horns 35 prior to movement ofthe lower portions of the arcs from the contacts 45. Upon the transferof each of the arcs in the separate extinguishing units 23 to the upperarc horn 35, the arc circuit is now changed and instead of flowingthrough the fixed contacts, the circuit will be from the terminal I3,the upper end plate 31, upper shunt coils I5, upper arc horn 35, movablecontact 45,'the flexible connector IS, the lower end plate 31, the lowershunt coil I5, connection 95, 91 joining the lower shunt coil of theuppermost unit with the upper shunt coil of the next adjacent unit. V

The connections for subsequent units are the same as those abovedescribed and need not be repeated. It should be noted that the shiftingof the upper end of thearc to the upper arc horn 35 in each of the units23 causes the upper shunt coil I5 to be inserted in the arc circuit andat the same time causes the series coil 55 of each unit to bedisconnectedirom the circuit. It'should also be noted that since thelower shunt coil I5 of the first unit is connected in series by theconnections 35, 91, to the upper shunt coil I5 of the next adjacent unit23 and that the lower shunt coil I5 of theflrst unit is also connectedto the lower end plate 31 which is at the same potential as the movingcontact 45 that as soon as the upper end of the arc shifts to the upperarc horn 35 that each of the lower shunt coils I5 with the exception ofthe lower shunt coil 15 of the lowermost unit 23 will also be insertedin the arc circuit. In other words, with the exception of the lowershunt coil 15 in the lowermost unit 23, both the upper and lower shuntcoil I5 become effective upon the mere shifting of the upper ends ofeach v of the arcs to the upper arc horn 35 of each unit.

As soon as the shunt coils I5 become thus energized, a strong radialmagnetic field is produced across the respective arc paths having itsmajor concentration at the .upper and lower ends of the paths so as tocompletely transfer the separate arcs drawn between the contacts 43 and45 on to the arc horns 35. Since the upper and lower shunt coils I5 aresimultaneously energized to complete the are shifting operation from themain contacts 43 and 45 on to the arc horns 35, a series coil in thelower end plate 31 of each unit is not required, with the exception ofthe lowermost unit 23 where it is desirable to utilize a series coilI53, since there is no subsequent adjacent unit having an upper shuntcoil I5 to which the lower shunt coil I5 of the last unit may beconnected. Thus the series coil I53 in the lowermost unit 23 serves toestablish a radial magnetic field at the lower portion of the arcpassage 29 of the lowermost unit until the arc is completely transferredfrom the main contacts 43 and 45 on to the arc horns 35. Once theseparate arcs are transferred to their respective arc horns 35, theelectrical circuit is as follows. Terminal I3, upper end plate 31, shuntcoil I5, upper arc horn 35, through the arc to the lower arc horn 35,lower shunt coil I5, connection 35, 51, the upper shunt coil I5, of thenext succeeding unit from whence the connections repeat for eachsucceeding unit until the lower arc horn 35 of the lowermost unit 23 is;reached. From this point on, the connection is through the lower shuntcoil I5, series coil I03 and the releasable contact I9.

From the foregoing description, it will be apparent that regardless ofthe current flowing through the main breaker contacts 43 and 45, in theevent that the contacts are separated and the arc extinguishing units 23are called upon to extinguish the are, there would always be a radialmagnetic field set up by the series coil 65 for initially moving atleast one end of the are on of the shunt coils 15 of eachunit so as toproduce a strong joint magnetic field necessary for moving the arclaterally with its ends playing upon the are horns 35 along the slot 25with a high velocity. Since the engagement of the arc with the arcquenching fluid contained inthe passage 23 produces fairly largequantities of gas which aid in extinguishing the arc, it is necessary toprovide means for relieving the pressure within the passage 25. In theapplication of R. C. Dickinson and W. M. Leeds, Serial No. 82,594, filedMay 29, 1936, and assigned to the assignee of this application, an arcextinguishing structure is shown wherein provision is made for ventingthe arc passage. In the instant application, similar venting means areshown which comprise suitable ports or passages as indicated at I23which designate a radial portion along one of the plates=25 which isconnected by an axial portion l2l extending through the plates 33 and31, as shown more particularly in Figs. 2 and 3. These passages permitthe escape of gas and are quenching liquid, and thereby prevent thepressure from becoming excessive within the posanem a sage is during theinterruption of extremely severe current overloads under which conditionfairlyilarge quantities of gas are evolved.

Although we have shown a particular are extinguishing structureembodying specific means for producingarc movement therein, it isto beunderstood that the same is for the purpose of illustration and that esand modifications may be made by those skilled in theart without 10departing from the spirit andsscope oi the appended claims. r r We claimas our invention: f 1.. In a circuit interrupter, a pair of separablecontact members for establishing spare, a pair of '15 are hornsofgenerally annular shape spaced a considerable distance apart forreceiving said arc, a coil in series with said contact members forproducing a magnetic field to move said arc on to said are horns, eachof said arc horns having a m curved arc path thereon between which saidare is adapted-to play in one long section, and a second coil in serieswith said are hornsi'or producing a radial magnetic field between saidare horns to move the arc. laterally along said curved a are paths. y

2. In a circuit interrupter, a plurality oi pairs of separable contactmembers ior establishing a l/ plurality of serially related arcs, acorresponding plurality of pairs oi arc terminals of generally acircular conformation between which said respectivearcs'a're-subsequently adapted to play, -.an-operating ,rod movablethrough the central portion of said are terminals for actuating saidpairs oi contact members, a coil in series with a each of said pairs oiseparable contacts for producing a magnetic field to move the said arcsindividually on to a'corresponding pair a: are terminals, and a secondcoil disposed about said operating rod and in series with each of said49 pairs of arc terminals to produce a radial magnetic field for movingeach are along its corresponding arc terminals, said second coils beingconnected for energizatipn upon the engagement of each arc with at leastone of the arc' terminals a'of its respective pairof'terminals.

. 3. In a circuit interrupter, a plurality pairs of separable contactmembers for establishing a plurality of serially related arcs, acorresponding plurality of pairs of arc terminals of generally annularshape for receiving the, ends of the respective arcs, a coil of annulariorm concentrically arrangedyith respect to said are terminals and incircuit with each pair of separable conon to oneare terminal of each ofsaid pairs of terminals, an operating rod movable through the centralportions or said are terminals and said coils forsimultaneouslyhctuating said separable so contact members, andanauxiliary coilior. each pair of arc terminals surrounding saidoperating rod and arranged to be inserted in its respective arc circuitupon the engagement of one end of the arc with one of its respective arcterminals for s setting up radialmagnetic fields for moving the arc'salong their respective arc is e 4. In a circuit interrupter, a pluralityof pairs of separable contact members for establishing a I plurality ofserially related arcs, a 'de 70 log plurality of pairs of arc terminalsfor receiving the ends: of therespective arcs, a coil in cir-.

is terminal-oi each of said pairs of terminals, and .a

pair-oiaunliaryeoilsioreachpairofarcterminalsarrangedtobeinsertedseriallyintheirrespectivearc circuits upon the engagement oi one x end oieacharcwithitsrespective arc terminal and also upon the subsequent engagement ofthe 5 other end at arc with its respective other arc terminal or settingup magnetic fields for moving-the arcs along their respective arc paths.

'member being adjacent-a contact member, op-

posedportionsorsaidarcterminalmembersadr jacent said separable contactmembers having inclinedarcpathetherecnwhich divergeinadirection awaytrom'said contact members, the 90 remaining opposed portions or said arcterminal members having substantially parallel arc paths thereon, a coilin circuitwith-saidcontact members for setting up a magnetic field tomove said arcontosaidarcter'minalmembersandasecgondcoilconnectedincircuit withsaidarc termi; nalmembers andldaptedtobeenergisedupon the engagement of said arc with at least one oi saidterminal members tor setting up a radial v magnetic field across saidslot to move said arc an laterally therealong in onesection with itsends in engagement with said are paths,

6; In an arc extinguisher, a plurality of plates of insulatingmaterlaleach 0! which has a curved narrow slot therethrough, said platesbeing ar- 3 ranged in a stack withwtheir slots in alignment todefine'the walls of a narrow generally annularly shaped passage, a pairof separable contacts iordrawing an are of considerable length longi;tudinally oi said passage, a pair of arc terminals 4" disposed in spacedrelsition within said passage for receiving the ends oi said are, a coilresponsive to the new of arc current between saidcon tact members forproviding a magnetic field to move atleast one end of said are onto oneoi said are terminals, and a second coil ve at least to the fiow of arccurrent between one or said contact members and one of saidarctermipairs for producing a radial magnetic field acrosssaidpassagetomovesaidarclaterallyinone long section therealong with itsends in engagement with said arc terminals.

'1. In an arc extinguisher, means of insulating material defining thewalls of a narrow generally annularly' shaped e, a pair of separablecontacts for drawing an arc longitudinally of said terminalineachendoi'saidpas sage to provide generally circularly shaped paths for theends of said arc, electromagnetic means initially in circuit with saidare for causing at so least one end thereof to be moved from one con-.

" tact member to once! saidarc terminals, asecsaid oneoisaidarcterminalsior causing said are to bemoved laterally along saidpassage with its ends in t with said are terminals, a material alongsaid passage which produces a gas when acted upon by an arc to aid inextinguishing 10 the arc, and vent means enabling the escape ofgasi'romsaidpassage.

-8. In a circuit interrupter, means of insulating material for defining,a generally ann'ularly shaped narrow slot, means for establishing anarc v s lengthwise of said slot, arc terminals within said slot adjacentsaid are establishing means for receiving the ends of said arc, a coilin circuit with said arc establishing means for setting up a magneticfield for moving said arc on to said are terminals, a second coil incircuit with said are terminals and adapted to be energized uponengagement of the arc-with at least one of said arc terminals forsetting up a radial magnetic field across said slot to whirl the arctherealong, said slot having a material therealong which gives oil a gaswhen acted upon by an arc to aid in extinguishing the arc, and ventpassages leading from said slot to enable gas to escape therefrom.

9. In a circuit breaker, a plurality of are extinguishing units, each ofsaid units comprising means of insulating material for defining a narrowpassage, means for simultaneously establishing an arc in each of saidpassages, said arcs having a series relationship with respect to eachother, arc terminals in each or said passages for the ends of the areestablished therein, means responsive to the initial arc current forproducing a magnetic field at each unit to cause each of said arcs to bemoved laterally into engagement with its respective arc terminals, meansfor each unit made operative by the engagement of at least one end ofeach of said arcs with one of its respective arc terminals for producinga magnetic field to move each of said arcs along its respective passage,and means along said passage which gives oil a gas when acted upon by anarc to aid in extinguishing the arc.

10. In a circuit breaker, a plurality o! are extinguishing units, eachof said units comprising means of insulating material for defining thewalls of a narrow arcuate passage, a pair 0! separablecontacts in eachof said passages, means connecting said pairs of contacts in series,means for causing the simultaneous separation oi said pairs of contactsto establish a series are in each of said passages, a pair of curvedspaced arc terminals in each of said passages for receiving the arcestablished therein, a coil in circuit with each pair of contacts andpositioned adjacent 7 one end of each of said passages for setting up awithin said passage into engagement with one of said are terminalstherein, a second coil positioned adjacent the first coil of each ofsaid units connected in circuit with one of said are terminals andadapted to be energized upon the en'- gagement of said one end of eacharc with the said one of said arc terminals for setting up a radialmagnetic field across each passage to rotate the arc therein along itsrespective arc terminals,

a material along each passage which gives oi! a gas when acted upon byan arc to aid in extinguishing the arc, and vent openings, leading fromeach passage to enable the escape of gas from said passages.

' 11. In a circuit breaker, a plurality of arc extinguishing units, eachof said units comprising means of insulating material for defining thewalls of a slot of generally annular shape, a pair of separable contactmembers in each slot, means connecting said contact members in series, acommon actuating member for simultaneously separating said pairs ofcontacts to establish a series arc in each of said slots, an are how ofgenerally circular shape positioned at each end of each of said slots, acoil situated at one end of each slot and in circuit with the pair ofcontact terminals therein for setting up a radial magnetic field acmeach slot to move at least one end of first-named field for moving thenoon to one of said are horns, an auxiliary coil situated adjacentopposed ends of each of said slots and positioned concentrically withrespect to said first coil, the auxiliary coil of each unit adjacent thefirst coil of each unit being connected to one of said'arc horns andadapted to be energized upon the transfer of the said end of the arefrom one of said separable contacts to the said one of said are hornsfor setting up a radial magnetic field across the respective slot, theother auxiliary coil of each unit being connected to the other arc hornand adapted to be energized upon the insertion into the circuit of thefirst auxiliary coil of a unit next adjacent for setting up a radialmagnetic field jointly with said first auxiliary coil of each unit tocause the other end of the arc to transfer to the other arc horn of itsrespective unit, and for moving the arc along the slot with its ends incontact with the arc horns contained therein, said first-named coil ofeach unit being disconnected from the arc circuit upon the transfer ofone end of each arc to one of the. arc horns.

12. In a circuit breaker, means of insulating material for defining thewalls of a narrow annularly shaped passage, a pair of contacts, saidcontacts being engageable for carrying the entire load current of theconnected circuit and separable to establish an are within said passage,arc terminals within said passage between which said are is adapted toplay, a coil in series with said contacts for setting up a radialmagnetic field across said passage to move said arc onto said areterminal means, and a second coil adapted to be inserted into the arccircuit upon the engagement of at least one end of the arc with one ofsaid are terminals for setting up a radial magnetic. field across saidpassage coextensive with said first magnetic field for rotating the arcin said passage.

13. In a. circuit breaker, means of insulating material for defining thewalls of a narrow annularly shaped passage, a pair of contacts, saidcontacts being engageable for carrying the entire load current of theconnected circuit and separable to establish an arc within said passage,arc terminals within said passage between which said are is adapted toplay, a coil in series with said contacts for setting up a radialmagnetic field across said passage to move said are onto said arcterminal means, and a second coil adapted to be inserted in the arccircuit upon the engagement of the arc with said are terminals forsetting up aradial magnetic field across said passage co-extensive andjointly operative? with said the arc laterally along said passage.

14. In a circuit interrupter, means of insulating material for definingthe walls of a narrow annularly-shaped passage, a. main circuit throughsaidinterrupter including a pair of contacts engageable or carrying theload current of the connected circuit and separable for establishing anare within said e, a branch circuitsaid branch circuit for moving saidare laterally' along saidarc terminal members, at least one of saidfirst-named coils being common to both the main and the branch circuits.

15. In a multiple break circuit interrupter, a plurality of arcextinguishing structures, a plurality of pairs of serially related?separable contacts for establishing an arc in each of said structures, apair of spaced arc terminal members within each of said structuresbetween which said arcs are adapted to be moved, a plurality of coilswithin each of said structures, each of said structures having at leastone coil connected in series with said separable contacts to establish afield in response to current fiow through said contacts for moving thearc onto said terminal members, and two additional coils each of whichis connected in series with one of said arc terminal members toestablish a magnetic field in response, to the current flowing betweensaid terminal members for moving the arc therealong, and means forconnecting one of said last-named coils of one structure in series withthe other lastnamed coil of an adjacent structure to thereby complete'abranch circuit through said interrupter for carrying the arc currentfollowing the separation of said pairs of contacts.

16. In a multiple break circuit interrupter, a plurality of arcextinguishing structures, a plurality of serially related separablecontacts for establishing an arc in each of said structures, a pair ofspaced arc terminal members within each arc extinguishing structure, acoil adjacent each arc terminal member and connected thereto adaptedwhen energized to produce a magnetic field for moving the arc withineach are extinguishing structure laterally between its respective arcterminal members, means for moving at least one end of each areestablished between said separable contacts onto one are terminal memberof each arc extinguishing structure, and circuit connections betweensaid coils, contacts and arc terminal members so arranged that upon thetransfer of said one end of each arc onto the said one are terminalmember of each are extinguishing structure saidcoils and arcs will beconnected in series circuit relation.

17. In a circuit interrupter, an arc extinguishing structure comprisingmeans of insulating material defining a narrow generally annularlyshaped arc passage, a circuit. through the interrupter for normallycarrying the entire load of the connected circuit comprising an annularcoil of low reactance disposed in coaxial relation with and adjacent toone end of said are passage and a pair of separable contacts within saidpassage, One of which is directly connected to and supported by saidcoil, a second circuit through the interrupter comprising an arcterminal member disposed at each end of said are passage and a coil ofrelatively higher reactance than said first coil disposed in coaxialrelation about said first coil and connected in series with one of saidarc terminal members, said first coil maintaining a radial magneticfield across said are passage during the fiow of current through saidseparable contacts and being effective to move an arc established by theseparation of said contacts onto said are terminal members, said secondcoil being'energized upon the transfer of the arc to at least one ofsaid are terminal members to provide a radial magnetic field acrosssaidarc passage to move the arc laterally therealong.

wm'maor M. LEEDS. BENJAMIN P. BAKER.

